The present invention relates to a system for controlling the air-fuel ratio of mixture supplied to an internal combustion engine having a supercharger, for a vehicle.
An air-fuel ratio control system for an engine having a supercharger is disclosed in Japanese patent application laid open No. 55-164741, in which the air-fuel ratio is controlled by supercharging pressure. Such a system has a disadvantage that the air-fuel ratio can not be controlled to a proper value in the entire operational range of the engine, causing problems, for example, impairing driveability of the vehicle.